1. Field of the Invention
The present invention relates generally to microscopic inspection methods and apparatus. The present invention relates more particularly to automated inspection systems for semiconductor manufacturing.
2. Description of the Background Art
A variety of methods have been used to examine microscopic surface structures of semiconductors. These have important applications in the field of semiconductor integrated circuit (IC) fabrication, where microscopic defects at a surface layer make the difference between a good or bad IC. For example, holes or vias in an intermediate insulating layer often provide a physical conduit for an electrical connection between two outer conducting layers. If one of these holes or vias becomes clogged, it will be impossible to establish this electrical connection. Automated inspection of the semiconductors is used to ensure a level of quality control in the manufacture of the integrated circuits.
An example of a conventional electron beam (e-beam) apparatus for an inspection system is described in U.S. Pat. No. 5,578,821, issued to Meisberger et al (the Meisberger patent). The disclosure of the Meisberger patent is hereby incorporated by reference in its entirety.